4 This has been completed up to 8dcc3739, except for:
5 803e389 rurban CYG17 utf8 paths
6 d9298c1 rurban mymalloc isn't thread safe
10 [ this is a template for a new perldelta file. Any text flagged as
11 XXX needs to be processed before release. ]
13 perldelta - what is new for perl v5.15.8
17 This document describes differences between the 5.15.7 release and
20 If you are upgrading from an earlier release such as 5.15.6, first read
21 L<perl5157delta>, which describes differences between 5.15.6 and
26 XXX Any important notices here
28 =head1 Core Enhancements
30 XXX New core language features go here. Summarise user-visible core language
31 enhancements. Particularly prominent performance optimisations could go
32 here, but most should go in the L</Performance Enhancements> section.
34 [ List each enhancement as a =head2 entry ]
36 =head2 Improved ability to mix locales and Unicode, including UTF-8 locales
38 An optional parameter has been added to C<use locale>
40 use locale ':not_characters';
42 which tells Perl to use all but the C<LC_CTYPE> and C<LC_COLLATE>
43 portions of the current locale. Instead, the character set is assumed
44 to be Unicode. This allows locales and Unicode to be seamlessly mixed,
45 including the increasingly frequent UTF-8 locales. When using this
46 hybrid form of locales, the C<:locale> layer to the L<open> pragma can
47 be used to interface with the file system, and there are CPAN modules
48 available for ARGV and environment variable conversions.
50 Full details are in L<perllocale>.
52 =head2 New function C<fc> and corresponding escape sequence C<\F> for Unicode foldcase
54 Unicode foldcase is an extension to lowercase that gives better results
55 when comparing two strings case-insensitively. It has long been used
56 internally in regular expression C</i> matching. Now it is available
57 explicitly through the new C<fc> function call (enabled by
58 S<C<"use feature 'fc'">>, or C<use v5.16>, or explicitly callable via
59 C<CORE::fc>) or through the new C<\F> sequence in double-quotish
62 Full details are in L<perlfunc/fc>.
64 =head2 C<_> in subroutine prototypes
66 The C<_> character in subroutine prototypes is now allowed before C<@> or
71 XXX Any security-related notices go here. In particular, any security
72 vulnerabilities closed should be noted here rather than in the
73 L</Selected Bug Fixes> section.
75 [ List each security issue as a =head2 entry ]
77 =head1 Incompatible Changes
79 XXX For a release on a stable branch, this section aspires to be:
81 There are no changes intentionally incompatible with 5.XXX.XXX
82 If any exist, they are bugs, and we request that you submit a
83 report. See L</Reporting Bugs> below.
85 [ List each incompatible change as a =head2 entry ]
87 =head2 Special blocks called in void context
89 Special blocks (C<BEGIN>, C<CHECK>, C<INIT>, C<UNITCHECK>, C<END>) are now
90 called in void context. This avoids wasteful copying of the result of the
91 last statement [perl #108794].
93 =head2 The C<overloading> pragma and regexp objects
95 With C<no overloading>, regular expression objects returned by C<qr//> are
96 now stringified as "Regexp=REGEXP(0xbe600d)" instead of the regular
97 expression itself [perl #108780].
99 =head2 Two XS typemap Entries removed
101 Two presumably unused XS typemap entries have been removed from the
102 core typemap: T_DATAUNIT and T_CALLBACK. If you are, against all odds,
103 a user of these, please see the instructions on how to regain them
108 XXX Any deprecated features, syntax, modules etc. should be listed here.
109 In particular, deprecated modules should be listed here even if they are
110 listed as an updated module in the L</Modules and Pragmata> section.
112 [ List each deprecation as a =head2 entry ]
114 =head1 Performance Enhancements
116 XXX Changes which enhance performance without changing behaviour go here. There
117 may well be none in a stable release.
119 [ List each enhancement as a =item entry ]
129 =head1 Modules and Pragmata
131 XXX All changes to installed files in F<cpan/>, F<dist/>, F<ext/> and F<lib/>
132 go here. If Module::CoreList is updated, generate an initial draft of the
133 following sections using F<Porting/corelist-perldelta.pl>, which prints stub
134 entries to STDOUT. Results can be pasted in place of the '=head2' entries
135 below. A paragraph summary for important changes should then be added by hand.
136 In an ideal world, dual-life modules would have a F<Changes> file that could be
139 [ Within each section, list entries as a =item entry ]
141 =head2 New Modules and Pragmata
151 =head2 Updated Modules and Pragmata
157 L<B> has been upgraded from version 1.33 to version 1.34.
159 C<B::COP> now has a C<stashflags> method, corresponding to a new internal
160 field added in 5.15.4 [perl #108860].
164 L<Compress::Raw::Bzip2> has been upgraded from version 2.045 to version 2.048.
168 L<Compress::Raw::Zlib> has been upgraded from version 2.045 to version 2.048.
172 L<Compress::Zlib> has been upgraded from version 2.046 to version 2.048.
176 L<DB_File> has been upgraded from version 1.824 to version 1.826.
180 L<diagnostics> has been upgraded from version 1.27 to version 1.28.
182 When searching for F<perldiag.pod>, it no longer uses paths that were only
183 relevant on Perl 5.004 and earlier.
187 L<ExtUtils::ParseXS> has been upgraded from version 3.12 to version 3.15.
189 The new version comes with important tools for sharing typemaps between
190 different CPAN distributions.
194 L<IPC::Cmd> has been upgraded from version 0.72 to version 0.76.
198 L<Math::Complex> has been upgraded from version 1.58 to version 1.59.
200 This avoids a new core warning.
204 L<Pod::Parser> has been upgraded from version 1.37 to version 1.51.
208 L<Time::HiRes> has been upgraded from version 1.9724 to version 1.9725.
210 C<Time::HiRes::stat()> no longer corrupts the Perl stack.
214 L<Unicode::UCD> has been upgraded from version 0.39 to 0.40.
216 The only change is to fix a formatting error in the Pod.
220 =head2 Removed Modules and Pragmata
232 XXX Changes to files in F<pod/> go here. Consider grouping entries by
233 file and be sure to link to the appropriate page, e.g. L<perlfunc>.
235 =head2 New Documentation
237 XXX Changes which create B<new> files in F<pod/> go here.
239 =head3 L<perlxstypemap>
241 The new manual describes the XS typemapping mechanism in unprecedented
242 detail and combines new documentation with information extracted from
243 L<perlxs> and the previously unofficial list of all core typemaps.
247 XXX Description of the purpose of the new file here
249 =head2 Changes to Existing Documentation
251 XXX Changes which significantly change existing files in F<pod/> go here.
252 However, any changes to F<pod/perldiag.pod> should go in the L</Diagnostics>
261 XXX Description of the change here
267 The following additions or changes have been made to diagnostic output,
268 including warnings and fatal error messages. For the complete list of
269 diagnostic messages, see L<perldiag>.
271 XXX New or changed warnings emitted by the core's C<C> code go here. Also
272 include any changes in L<perldiag> that reconcile it to the C<C> code.
274 [ Within each section, list entries as a =item entry that links to perldiag,
279 L<Invalid version object|perldiag/"Invalid version object">
282 =head2 New Diagnostics
284 XXX Newly added diagnostic messages go here
292 XXX L<message|perldiag/"message">
302 XXX L<message|perldiag/"message">
306 =head2 Changes to Existing Diagnostics
308 XXX Changes (i.e. rewording) of diagnostic messages go here
314 XXX Describe change here
318 =head1 Utility Changes
320 XXX Changes to installed programs such as F<perlbug> and F<xsubpp> go
321 here. Most of these are built within the directories F<utils> and F<x2p>.
323 [ List utility changes as a =head3 entry for each utility and =item
324 entries for each change
325 Use L<XXX> with program names to get proper documentation linking. ]
337 =head1 Configuration and Compilation
339 XXX Changes to F<Configure>, F<installperl>, F<installman>, and analogous tools
340 go here. Any other changes to the Perl build process should be listed here.
341 However, any platform-specific changes should be listed in the
342 L</Platform Support> section, instead.
344 [ List changes as a =item entry ].
356 XXX Any significant changes to the testing of a freshly built perl should be
357 listed here. Changes which create B<new> files in F<t/> go here as do any
358 large changes to the testing harness (e.g. when parallel testing was added).
359 Changes to existing files in F<t/> aren't worth summarising, although the bugs
360 that they represent may be covered elsewhere.
362 [ List each test improvement as a =item entry ]
372 The test suite for typemaps has been extended to cover a larger fraction of
377 =head1 Platform Support
379 XXX Any changes to platform support should be listed in the sections below.
381 [ Within the sections, list each platform as a =item entry with specific
382 changes as paragraphs below it. ]
386 XXX List any platforms that this version of perl compiles on, that previous
387 versions did not. These will either be enabled by new files in the F<hints/>
388 directories, or new subdirectories and F<README> files at the top level of the
393 =item XXX-some-platform
399 =head2 Discontinued Platforms
401 XXX List any platforms that this version of perl no longer compiles on.
405 =item XXX-some-platform
411 =head2 Platform-Specific Notes
413 XXX List any changes for specific platforms. This could include configuration
414 and compilation changes or changes in portability/compatibility. However,
415 changes within modules for platforms should generally be listed in the
416 L</Modules and Pragmata> section.
420 =item XXX-some-platform
426 =head1 Internal Changes
428 XXX Changes which affect the interface available to C<XS> code go here.
429 Other significant internal changes for future core maintainers should
432 [ List each change as a =item entry ]
442 =head1 Selected Bug Fixes
444 XXX Important bug fixes in the core language are summarised here.
445 Bug fixes in files in F<ext/> and F<lib/> are best summarised in
446 L</Modules and Pragmata>.
448 [ List each fix as a =item entry ]
454 C<~~> now correctly handles the precedence of Any~~Object, and is not tricked
455 by an overloaded object on the left-hand side.
459 C<stat _> no longer warns about unopened filehandles [perl #71002].
463 C<stat> on an unopened filehandle now warns consistently, instead of
464 skipping the warning at times.
468 A change in an earlier 5.15 release caused warning hints to propagate into
469 C<do $file>. This has been fixed [rt.cpan.org #72767].
473 Starting with 5.12.0, Perl used to get its internal bookkeeping muddled up
474 after assigning C<${ qr// }> to a hash element and locking it with
475 L<Hash::Util>. This could result in double frees, crashes or erratic
480 In 5.15.7, some typeglobs in the CORE namespace were made read-only by
481 mistake. This has been fixed [rt.cpan.org #74289].
485 C<-t> now works when stacked with other filetest operators [perl #77388].
489 Stacked filetest operators now only call FETCH once on a tied argument.
493 C</.*/g> would sometimes refuse to match at the end of a string that ends
494 with "\n". This has been fixed [perl #109206].
498 Method calls whose arguments were all surrounded with C<my()> or C<our()>
499 (as in C<<$object->method(my($a,$b)) >>) used to force lvalue context on
500 the subroutine. This would prevent lvalue methods from returning certain
501 values. Due to lvalue fixes earlier in the 5.15.x series, it would also
502 prevent non-lvalue methods from being called [perl #109264].
505 This bug I<did> affect earlier stable releases. It is just the last
506 sentence that does not apply to 5.14.
510 =head1 Known Problems
512 XXX Descriptions of platform agnostic bugs we know we can't fix go here. Any
513 tests that had to be C<TODO>ed for the release would be noted here, unless
514 they were specific to a particular platform (see below).
516 This is a list of some significant unfixed bugs, which are regressions
517 from either 5.XXX.XXX or 5.XXX.XXX.
519 [ List each fix as a =item entry ]
531 XXX If any significant core contributor has died, we've added a short obituary
534 =head1 Acknowledgements
536 XXX Generate this with:
538 perl Porting/acknowledgements.pl v5.15.7..HEAD
540 =head1 Reporting Bugs
542 If you find what you think is a bug, you might check the articles
543 recently posted to the comp.lang.perl.misc newsgroup and the perl
544 bug database at http://rt.perl.org/perlbug/ . There may also be
545 information at http://www.perl.org/ , the Perl Home Page.
547 If you believe you have an unreported bug, please run the L<perlbug>
548 program included with your release. Be sure to trim your bug down
549 to a tiny but sufficient test case. Your bug report, along with the
550 output of C<perl -V>, will be sent off to perlbug@perl.org to be
551 analysed by the Perl porting team.
553 If the bug you are reporting has security implications, which make it
554 inappropriate to send to a publicly archived mailing list, then please send
555 it to perl5-security-report@perl.org. This points to a closed subscription
556 unarchived mailing list, which includes
557 all the core committers, who will be able
558 to help assess the impact of issues, figure out a resolution, and help
559 co-ordinate the release of patches to mitigate or fix the problem across all
560 platforms on which Perl is supported. Please only use this address for
561 security issues in the Perl core, not for modules independently
566 The F<Changes> file for an explanation of how to view exhaustive details
569 The F<INSTALL> file for how to build Perl.
571 The F<README> file for general stuff.
573 The F<Artistic> and F<Copying> files for copyright information.